Refrigerating apparatus having means for preventing condensation of moisture on the door



Sept. 8. 1953 2 Sheets-Sheet 1 CONDENSATI Filed Feb. 7, 1952 tors? arrz's n Pros ell o .17: 2/272 rlest 65a 'pG/S/E pt- 8, 1 3 c. D. HARRIS ET AL 2,651,187

REFRIGERATING APPARATUS HAVING MEANS FOR PREVENTING CONDENSATION OF MOISTURE ON THE DOOR Filed Feb. 7, 1952 2 SheetsSheet 2 .lfizhtonsf' Charles Marrz's (Jo/E72 R. PTOSeI? PMQ, W

Patented Sept. 8, 953

REFRIGERATIN G APPARATUS HAVING MEANS FOR PREVENTING CONDENSA- TION OF MOISTURE ON THE DOOR Charles D. Harris and John R. Prosek, Evansville, Ind., assignors to International Harvester Company, a corporation of New Jersey Application February 7, 1952, Serial No. 270,426

Claims. 1

This invention relates to refrigeration apparatus and more particularly to a refrigerator cabinet having means for preventing condensation of moisture on the compartment door thereof.

Refrigerator cabinets are in many cases constructed in such a manner that the outer surfaces of a compartment door will be cooled to temperatures below the dew point of the surrounding air whereby moisture carried by the air will be cooled and condensed on the door surfaces. This is an undesirable situation. since the moisture must be removed from the door periodically in order to prevent damage to the finish of the door and to prevent drippage onto the floor below the cabinet. Such condensation is frequently encountered on the storage type refrigerator cabinet having a vertically disposed door, as well as the low temperature freezer type cabinet having a horizontally disposed door. The present invention provides a means for preventing condensation on the compartment door of either type of cabinet as will be disclosed hereinafter.

One object of the present invention is to provide a refrigerated cabinet with means for preventing the outer surfaces of a compartment door from being cooled to. the dew point of the surrounding air.

Another object of the invention is to provide the cabinet with a secondary coil-which is attached in heat exchange relation with the portions of the door which would normally be cooled to the dew point of thesurrounding air.

A further object of the invention is to provide a boiler which is connected to said secondary coil and is adapted to be heated bythe refrigeraa tion system of thecabinet. ,v H r A still further object is to, charge the boiler and secondary coil with a volatile fluid which will circulate therethrough as heat is added to the boiler.

A still further object ofthe invention is to provide a heat exchange element which is disposed in heat exchange relation withsaid boiler and is heated by the hot compressed gases of said refrigeration system.

A still further object of the invention is to secure said boiler to said door and to secure said heat exchange element to said cabinet in such a manner that the door can be opened and closed.

A still further object of the invention is to provide means for biasing said heat exchange element into contact with said boiler when the door is closed.

Further objects and advantages of the present vention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a vertical sectional view of a refrigerated cabinet showing a preferred embodiment of the invention.

Fig. 2 is a horizontal sectional view taken along line 2-2 of Fig. 1.

Fig. 3 is a vertical sectional view of the lower portion of the refrigerated cabinet showing a modification of the invention.

Fig. 4 is a plan view of the compressor shown in Fig. 3.

Fig. 5 is a vertical sectional view of the lower portion of the refrigerated cabinet showing another modification of the invention.

Fig. 6 is a rear elevational view of the cabinet shown in Fig. 5.

Fig. 7 is an enlarged fragmentary view of the lower portions of the door and cabinet of Fig. 1. F Fig. 8 is a perspective view of the boiler of Fig. 9 is a cross-sectional view of the boiler and heat exchanger of Fig. 7.

Referring to the drawing for a detailed description of the invention, Fig. 1 is a sectional view of a refrigerator cabinet I 0 in which the invention is incorporated. The cabinet I!) comprises an outer shell H and an inner liner I2 which is disposed within the outer shell II in spaced relationship. The space between the walls of the inner liner l2 and the outer shell II is filled with a suitable insulating material l3 outer shell I l and the inner liner l2 are joined by a breaker strip member l5 and a compartment door [6 is pivotally hinged to the cabinet. The door [6 comprises an outer metallic pan I1 having a front curved portion I8, top wall I 9, side wall 20, bottom wall 2|, and side wall 22. These walls are provided with inturned flanges 23, 24.

I! with the edges thereof being secured to the inturned flanges 23, 24, 25, and 26. Insulating material 28 fills the space between the outer pan I1 and the inner pan 2! in order to reduce the transfer of heat therebetween.

A plate type evaporator 29 is positioned in the upper portion of the compartment l4 and may be secured to the inner liner in any suitable fashion. A machinery chamber 33 is positioned below the food storage compartment [4 and a hermetically sealed motor-compressor unit 3| i secured therein. A flue type plate condenser 3 is secured to the rear wall of the outer shell H whereby cooling air will circulate upwardly between theouter shell H and the condenser 32 Suitable means may be provided for controlling the operation of the motor-compressor unit 3 when cooling of the food storage compartment I4 is required. The evaporator 29, the condenser 32 and the compressor unit 3| are connected by refrigerant carrying conduits order to complete the refrigeration system.

The lower portion of the inner door pan 21 is provided with an opening therethrough into which a boiler member 33 is positioned. The boiler 33 is a hollow member formed in the shape of a half cylinder having a vertical sidewall 34, a curved side wall 35, and end walls 33 and 3?. The boiler extends horizontally across the door l6 and is permanently secured to the lower inturned flange 25 of the outer door pan ll and to the lower edge 38 of the inner pan 2'! by welding or the like. A continuous coil 39 has one end 40 connected into the lower portion of the end wall 36 of the boiler 33 and the other end 4| connected into the top portion of the end wall 31. The coil has a first leg or vertical portion 42 which extends upwardly along Side wall 23 of the door pan and is secured in heat exchange relation to the flange 24 and side wall 23. The coil 39 then runs across the top of the door and is secured in heat exchange relation to the flange 23 and top wall l9. A second vertical portion 43 of the coil turns and extends downwardly between side wall 22 and flange 26 to which it is secured in thermal contact.

The front wall of the machinery chamber 33 is open and a heat exchanger 44 is positioned therein. It is contemplated that the heat exchanger 44 be constructed in the form of a hollow half cylinder with substantially the same dimensions as the boiler 33. The heat exchanger 44 is provided with a vertical wall 45, curved wall 46, and two end walls 41 and 48. Two spaced apart brackets 49 are secured to the top portion of wall 46 and two other spaced apart brackets 59 are secured to the lower portion of wall 46. Two mounting brackets are secured to the lower wall 52 of the outer shell H and each one is provided with an inwardly extending eyelet or projection 53. The bottom wall 54 of the machinery chamber 30 is provided with an upwardly inclined edge portion 55 which has two spaced apart projections 56 extending therefrom. The heat exchanger 44 is mounted in place by four coiled springs 51, two of which have their outer ends fastened to the projections 53 of brackets 5| and their inner ends fastened in projections 58 provided in brackets 43. The outer ends of the other two springs are secured to the projections 56 of bottom wall 54 whereas their inner ends are secured in projections 53 provided in brackets 50. When the door I6 is in closed position, the springs 51 will bias heat exchanger 44 toward boiler 33 so that their vertical walls 45 and 34 respectively will be held tightly together. When the door |3 is opened the boiler 33 will be moved away from the heat exchanger 44 and the springs 51 will bias the heat exchanger 44 forwardly. As the door I6 is then closed, the springs 51 will again bias the heat exchanger 44 against the boiler 33.

In the embodiment shown in Figs. 1, 2, 7, 8, and 9, the outlet of the compressor unit 3| is connected by conduit 63 to end 41 of the heat exchanger 44 and the inlet of the condenser 32 is connected to the end 48 of the heat exchan 44 by conduit 6!. The conduits E0 and 3| are provided with looped portions 62 and 63 which will bend without damage thereto whenever the heat exchanger 44 is moved by the springs 3'1. During the operation of the refrigeration system, compressed refrigerant gas from the motorcompressor unit 3| will be conveyed to the heat exchanger 44 by conduit 63, then passed to the condenser 32 by the conduit 6| where it will be cooled and condensed by cooling air surroundin the condenser 32. The liquefied refrigerant is then metered by a capillary tube 34 into he evaporator 29 where it will absorb heat from the food storage compartment I4 and be vaporized. After circulating through the evaporator 29, the refrigerant is returned to the compressor 3| by conduit 65 to again be compressed and passed through the refrigeration system.

As the hot compressed refrigerant gases flow through the heat exchanger 44, it will be heated to a high temperature and part of the heat will be conducted to boiler 33. The boiler 33 is partially filled with a liquid refrigerant, or other volatile liquid, which will be heated by the heat exchanger 44 to its boiling point. As the refrigerant boils, the vapors therefrom will flew upwardly through the vertical portion 43 of the coil 39, then across the top portion thereof from which it will be returned by the vertical portion 42 to the boiler 33. The side walls 22, I9, and 23 and the inturned flanges 26, 23, and 24 are all disposed in close proximity to the refrigerated compartemnt [4 of the cabinet. Even though the outer door pan l! is insulated from the refrigerated compartment l4, it has been found that the side walls and flanges of the outer door pan will sometimes be cooled below the dew point of the surrounding air and moisture will condense thereon if this temperature is maintained. This is prevented by the present invention by the secondary coil 39 which is held in thermal contact with the outer door pan 'As the refrigerant vapors circulate therethrough, they will absorb heat from the cold portions of the outer door pan l1 and be condensed. This will heat the door pan above the dew point of the air whereby condensation of the moisture from the air will be prevented. The condensed refrigerant will circulate back to the boiler. 33 where it will again be vaporized by the heat from the heat exchanger 44 and be recirculated through the coil 39. The secondary coil 39 is illustrated in but one form, but it is to be understood that it could be bent into any number of forms and positioned in heat exchange relation with any other portion of the door l6 upon which moisture might condense.

Another embodiment of the invention is illustrated in Figs. 3 and 4 of the drawing. The heat exchanger 44 is not connected directly into the refrigeration system but is connected to a hollow circular shaped boiler 66 by conduits 3'! and 68. The motor-compressor unit 3| is connected to the condenser 32 by a conduit 69. The boiler 63 fits around the motor-compressor unit 3| and is provided with a pair of straps 10 which are fastened to the ends of the boiler 83. The straps 13 are provided with offset end portions H having apertures therethrough into which a nut and bolt assembly L2 fastened. By tightening the as- 5. sembly 12, the boiler 66 will be held in contact with the motor-compressor unit 3| and will be heated thereby. The boiler 66 is partially filled with a volatile liquid or liquid refrigerant which will absorb heat from the compressor unit 3| and be vaporized. This refrigerant will be conveyed by the conduits 6! and 68 through heat exchanger 44 where it will be condensed by emitting heat to the boiler 33 and then returned to boiler 66 to repeat the cycle. The refrigerant within boiler 33 will be vaporized and will circulate through the secondary coil 39 in the manner explained hereto fore. The other elements of this embodiment are the same as those shown in Figs. 1, 2, 7, 8, and 9 and are designated by like reference numerals.

A third illustration is shown in Figs. and 6 of the drawings. The nected by conduits 13 and 14 to a boiler '15 which is fastened to the back of the condenser 32 by a pair of straps 16 and 11. The boiler 15 comprises a hollow elongated casing which is partially filled with a liquid refrigerant or other volatile fluid. During operation of the refrigeration system, the condenser 32 will heat the liquid within the boiler 15 and cause it to boil. The vapors generated within the boiler 15 will be conveyed by the conduits 13 and 14 through the heat exchanger 44 where they will be cooled by the'emitting heat to the boiler 33. From the heat exchanger 44, the liquid will be returned to the boiler 15 and will repeat the cycle. The refrigerant within boiler 33 will circulate through the secondary circuit as explained heretofore.

From the above description, it. is readily seen that the secondary coil 39 will operate to heat portions of the refrigerator'door I Gwhich are subjected to low temperatures whereby condensation of moisture from the surrounding air will be prevented. The heat required for the operation of the secondary coil 39 is absorbed fromthe high side of the refrigeration systemv so that ,no external heat supply is necessary. The secondary coil 39 will also improve the efficiency of the refrigeration system since the refrigerant within boiler 33 will absorb heat from the hot compressed gases within the heat exchanger 44 so that the high side pressure and temperature will be maintained within a lower range.

While the invention has been shown in three forms, it will be obvious to those skilled in the art that is is not so limited but is susceptible to various changes and modifications without departing from the spirit thereof, and it is therefore desired that only such limitations be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What is claimed is:

1. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a refrigeration system for cooling said compartment, a first heat exchange unit fixedy secured to said door, a coil positioned in heat exchange relation to said door with the ends thereof connected to said first heat exchange unit, said first heat exchange unit being partially filled with a volatile liquid, a second heat exchange unit movably secured to said cabinet and being associated with said refrigeration system so that it is heated thereby, and means for biasing said second heat exchange unit into contact with said first heat exchange unit so that said volatile liquid will be vaporized and circulated through said tube.

2. In a refrigerated cabinet having a storage heat exchanger 44 is con-' compartment, 2, door for closing saidcompartment, a refrigeration system for cooling said compartment, a boiler fixedly secured to said door, a coil positioned in heat exchange-relation to said door with the ends thereof connected to said boiler, said boiler being partially filled with a volatile liquid, a heat exchange element movably secured to said cabinet by resilient mounts whereby it is held in contact with said boiler when the door is in closed position, and means for heating said heat exchange element so that the volatile liquid in said boiler will be vaporized and circulated through said tube.

3. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a refrigeration system for cooling said compartment, a boiler fixedly secured to said door, a coil positioned in heat exchange relation to said door with the ends thereof connected to said boiler, said boiler being partially filled with a volatile liquid, a heat exchange element movably secured to said cabinet by resilient mounts whereby it is held in contact with said boiler when the door is in closed position, and means for trans ferring heat from said refrigeration system to said heat exchange unit, said boiler being heated by said heat exchange unit whereby said volatile liquid will be vaporized and circulated through said tube.

4. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a refrigeration system for cooling said compartment, a boiler fixedly secured to the lower portion of said door, exchange relation to said door with the ends thereof connected to said boiler, said boiler beingv partially filled with a volatile liquid, a heat exchange element movably secured to said cabinet below said compartment, means for biasing said heat exchange element into contact Withsaid boiler when the door is in closed position, and

means for transferring heat from said refrigera tion system to said heat exchange element, said boiler being heated by said heat exchange unit whereby said volatile liquid will be vaporized and circulated through said tube.

5. In a refrigerated cabinet having a storage compartment, a compartment door comprising an outer pan and an inner pan, said inner pan having an opening therethrough, a boiler secured within said opening, a coil positioned in heat exchange relation to a portion of said outer pan with the ends thereof connected to said boiler, said boiler being partially filled with a volatile liquid, a heat exchange unit secured to said cabinet, means for biasing said heat exchange element and said boiler together when the door is in closed position, and means for supplying heat to said heat exchange unit so that the volatile liquid within said boiler will be vaporized and circulated through said tube.

6. In a refrigerated cabinet having a storage compartment, a compartment door comprising an outer pan and an inner pan, the outer marginal edges of said outer pan formed to form side walls extending thereabout, said inner pan having an opening therethrough, a boiler secured within said opening, a coil positioned in heat exchange relation to said side walls of said outer pan with the ends thereof connected to said boiler, said boiler being partially filled with a volatile liquid, a heat exchange unit secured to said cabinet, means for biasing said heat exchange element and said boiler together when the door is in closed position, and means for transa coil positioned in heatass-1,12,?

ferring heat from said refrigeration system to said heat exchange unit, said boiler being heated by said heat exchange unit whereby said volatile liquid will be vaporized and circulated through said tube.

'7. In a refrigerated cabinet having a storage compartment, a compartment door comprising an outer pan and an inner pan which has an opening through the lower portion thereof, a boiler fixedly secured within said opening, a coil positioned in heat exchange relation to the outer marginal edges of said outer pan, said coil being connected to said boiler which is partially filled with a volatile liquid, a heatexchange element movably secured to said cabinet below said compartment, means for biasing said heat exchange element against said boiler when said door is in closed position, and means for transferring heat from said refrigeration system to said heat exchange unit, said boiler being heated by said heat exchange unit whereby said volatile liquid will be vaporized and circulated through said tube.

8. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a coil positioned in heat exchange relation with said door, a refrigeration system for cooling said compartment, said coil being connected to a boiler which is secured to said door and partially filled with a volatile liquid, a heat exchange unit movably secured to said cabinet and being connected into the high side of said refrigeration system whereby the high pressure refrigerant will flow therethrough, and means for biasing said heat exchange unit into contact with said boiler so that said volatile fluid will vaporize and circulate through said tube.

9. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a coil positioned in heat exchange relation with said door, a refrigeration system comprising a compressor, condenser and evaporator, said coil being'connected'to a first boiler which is secured to said door and partially filled with a volatile liquid, a heat exchanger movably secured to said cabinet, said heat exchanger being connected to a second boiler which is fastened in heat exchange relation to said compressor, said second boiler being partially filled with a volatile liquid which will be vaporized by heat from the compressor and circulated through said heat exchanger, and means for biasing said heat exchange unit into contact with said first boiler so that the liquid in said'first boiler will be vaporized and circulated through saidtube.

10. In a refrigerated cabinet having a storage compartment, a door for closing said compartment, a coil positioned in heat exchange relation with said door, a refrigeration system comprising a compressor, condenser and evaporator, said coil being connected to a first boiler which is secured to said door and partially filled with a volatile liquid, a heat exchanger movably secured to said cabinet, said heat exchanger being connected to a second boiler which is fastened in heat exchange relation to said condenser, said second boiler being partially filled with a volatile liquid which will be vaporized by heat from the condenser and circulated through said heat exchanger, and means for biasing said heat exchange unit into contact with said first boiler so that the liquid in said first boiler will be vaporized and circulated through said tube.

CHARLES D. HARRIS. JOHN R. PROSEK.

References Cited in the file of this patent UNITED STATES PATENTS 

